Although early changes which occur during the smoking of marijuana are more likely to be indicative of its mode of action, the smoking phase of marijuana use has largely been ignored and very little is known regarding what happens to a human subject during this process. This study detailed the effects of smoking marijuana cigarettes on a variety of systems including physiologic effects, behavior and hormonal systems. In addition, blood and saliva levels were determined during and after smoking. Blood and saliva levels were compared to drug-induced effects and hormonal changes. The results from this study provide a comprehensive assessment of marijuana's effects that occur both during and after smoking and offer important insight to the mode of action of this widely abused drug.